Set stem mechanism for watches

ABSTRACT

A set stem mechanism for watches comprising a set stem having a set pinion integral therewith and a shaped body portion which is designed for engagement with a stem bracket in either a set or an idle position. A stem release sleeve is slidably mounted about the set stem to contact the bracket disengaging it from the stem in order to facilitate removal of the crown and stem assembly.

Unite States Patent Grohoski [4 1 Jan. 18, 1972 [541 SET STEM MECHANISM FOR 1,292,441 l/l919 Depollier ..58/95 T WA CHES FOREIGN PATENTS OR APPLICATIONS 1t:R d.GhklWtrt,C. [72] J a e 16,784 11/1915 Great Britain ..58/95 [73] Assignee: Tlmex Corporatlon, Waterbury, Conn. [22] Filed: Apr. 3 70 Primary Examiner-Stephen J. Tomsky Assistant Examiner-George H. Miller, Jr. 1 PP 27,523 Attorney-Richard A. Joel 52 vs. (I ....58/99 1 ABSTRACT [51] Int. Cl. ..G04b 37/06 A set stem mechanism for watches com pnsmg a set stem hav [58] 0f 67, a Set p i g l therewith d a Shaped y p i which is designed for engagement with a stem bracket in [56] References Cited either a set or an idle position. A stem release sleeve is slidably UNITED STATES PATENTS mounted about the set stem to contact the bracket disengaging it from the stem in order to facilitate removal of the crown t and tem assembly 1,926,713 9/1933 Cochin .....58/67 398,957 3/1889 Faxon ..58/98 X 5 Claims, 3 Drawing Figures PATENTED mu 8 m2 SHEU 1 [IF 2 INVILYTOR RA YMONO J. GROHOSKI BY ATTORNEY FIG. I

PATENTEDJAHBISYZ sum 2 or 2 A TTORNE Y INVENTOR. RAYMOND J. GROHOSKI BY SET STEM MECHANISM FOR WATCHES BACKGROUND OF THE INVENTION The present invention relates to watches and more particularly to a set stem mechanism for watches.

The prior art includes U.S. Pat. Nos. 287,001 and 1,292,441 which disclose various set stem arrangements. These patents are merely of general interest, however, and the present invention represents a distinct improvement thereover. The set stem mechanism of the present invention eliminates the need for special tooling to remove the crown and stem assembly and also minimizes the possibility of damage to the stern.

Other prior art of interest are U.S. Pat. Nos. 1,409,067 and 2,480,843. U.S. Pat. No. 1,409,067 pertains to oil well machinery and discloses a sleeve which is designed to release a locking member mounted about a body member. U.S. Pat. No. 2,480,843 discloses a locking plug and jack having a sleeve arrangement slidable on a stem to bias the lock spring arms to a release position. These patents while illustrating various mechanical structures in other fields do not pertain to watches and the distinct problems encountered in this field.

SUMMARY OF THE INVENTION The present invention pertains to a set stem mechanism for watches comprising a set stem having a shaped body portion with locking portions thereon to be engaged by the legs of a stern bracket in either a set or an idle position. A set pinion is formed integrally with the stem and engages the crown gear of the minute wheel when the stem is in a set position. A stem release sleeve is slidably mounted about the stem to cam apart the legs of the stem bracket to facilitate removal of the crown and stem assembly.

Accordingly, it is an object of this invention to provide a new and improved set stem mechanism for watches which is lest costly, exhibits improved performance characteristics and is more readily repaired.

Other objects and advantages may be seen from the following description when viewed in conjunction with the drawings described below.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the invention with portions of the drawing cut away to show the important parts thereof;

FIG. 2 is a view similar to FIG. 1 showing the stern release sleeve of the invention in an operative position; and,

FIG. 3 is a cutaway side view of the subject set stem mechanism taken along the line 3-3 of FIG. 2.

DETAILED DESCRIPTION Referring now to'the drawings, the set stem mechanism of the present invention comprises a set stem having one end extending outwardly from the watch 11 and having a crown 12 mounted on the extremity thereof. The other end of the stem 10 is joumaled in a bearing 13 within the watch 11. The set stem 10 includes a substantially cylindrical body portion 14 and a protruding locking portion 16 which forms a recess 17 together with enlarged body portion 18. The stem 10 further includes a tapering portion 19 which extends from enlarged portion 18 to the body section 21. A set pinion 22 is formed integrally with the stem 10 between body section 21 and the end portion 23.

The set stem 10 is held in place by a pincer-type stem bracket 24 which engages protruding portion 16 in an idle position and when the stem 10 is retracted to a set position the bracket 24 engages one surface 26 of enlarged portion 18. The tapered surfaces 27 and 28 of the locking portion 16 cam the bracket 24 into a particular position during the to and fro movement of the stem 10. The base 29 of the bracket 24 includes the bearing means 13 for the stem 10.

A stem release sleeve 31 is slidably mounted about the stem 10. The sleeve 31 includes a countersunk portion 32 which clears locking portion 16 and an elongated aperture 33 slidable along body portion 14. The leading edge 34 of the sleeve is tapered to facilitate engagement with the curved end portions 36 of the bracket 24 forcing the pincerlike legs 37 apart. This releases the stem 10 permitting rapid removal of the crown and stem assembly from the watch 11 without the use of special hand tools. The possibility of damage to the stem bracket 24 is also minimized.

In order to set the watch 11, the set stem 10 is retracted by grasping the crown l2 and pulling away from the watch 11. The surface 27 of locking portion 16 forces the curved end portion 36 of the stem bracket 24 outwardly until surface 28 is reached. The ends 36 of bracket 24 then drop into the recessed portion 17 between the outwardly extending portions 16 and 18 on the stem 10.

In this position, the set pinion 22 engages the crown gear 38 of the minute wheel 39. The minute pinion 41 which is coupled to the minute wheel 39 then transmits the motion to the hour wheel 42. The minute wheel 39 and the hour wheel 42 are both supported for rotation in the front frame 43. The dial frame 44 holds the minute wheel 39 in place assuring proper engagement of crown gear 38 with stem pinion 22.

As shown in FIGS. 2 and 3, if it is desired to release the stem 10, the sleeve 31 is urged in the indicated direction into the watch 11 between the from frame 43 and the train bridge 46. As mentioned above, the legs 37 of the bracket 24 are forced apart freeing the stem 10 in a single quick operation without the use of special tools. This greatly facilitates repair and as sembly of the watch 11. Furthermore, the stem design itself eliminates many separate parts and provides a more accurate and less expensive means for setting a watch 11.

It is to be understood that the above-described arrangements are merely illustrative examples of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

I claim:

1. A set stern mechanism for watches comprising:

a set stem having an elongated body portion at the end protruding from the watch case, an intermediate locking portion having a pair of sloping faces, and a second end portion,

a set stem bracket, having a base portion including an aperture extending therethrough to be engaged by the second end portion of the set stem and a pair of upwardly extending legs which engage the sloping faces locking portion of the set stem, and

a substantially cylindrical stem release sleeve, said sleeve being slidable along the body portion of the stem to engage and spread apart the legs of the stem bracket thereby releasing the stem from the bracket.

2. A set stem mechanism in accordance with claim 1 wherein:

the set stem further includes a set pinion formed integrally therewith said pinion being journaled for rotation in the stern bracket aperture, and

the stem release sleeve includes a countersunk entrance portion which clears the locking portion of the set stem and tapered entrance surfaces to facilitate release of the stem bracket legs from the locking portion as the legs are forced outwardly therefrom by the movement of the sleeve.

3. A set stern mechanism in accordance with claim 2 wherein: p

the set stem includes an enlarged intermediate portion to act as a stop for the stern release sleeve, and, the

the locking portion comprises a protruding portion having a first face sloping outwardly from the elongated body portion of the stem along which the legs move during setting and a sloping portion extending in the opposite direction back to the stem body, forming a recess with the enlarged body portion.

4. A set stem mechanism in accordance with claim 2 wherein:

setting bringing the stem pinion into mesh with the crown gear for effecting movement of the minute wheel, and

the locking portion comprises a protruding portion which forces the stern legs apart from a first locked position until the legs move into a second locked position for setting. 

1. A set stem mechanism for watches comprising: a set stem having an elongated body portion at the end protruding from the watch case, an intermediate locking portion having a pair of sloping faces, and a second end portion, a set stem bracket, having a base portion including an aperture extending therethrough to be engaged by the second end portion of the set stem and a pair of upwardly extending legs which engage the sloping faces locking portion of the set stem, and a substantially cylindrical stem release sleeve, said sleeve being slidable along the body portion of the stem to engage and spread apart the legs of the stem bracket thereby releasing the stem from the bracket.
 2. A set stem mechanism in accordance with claim 1 wherein: the set stem further includes a set pinion formed integrally therewith said pinion being journaled for rotation in the stem bracket aperture, and the stem release sleeve includes a countersunk entrance portion which clears the locking portion of the set stem and tapered entrance surfaces to facilitate release of the stem bracket legs from the locking portion as the legs are forced outwardly therefrom by the movement of the sleeve.
 3. A set stem mechanism in accoRdance with claim 2 wherein: the set stem includes an enlarged intermediate portion to act as a stop for the stem release sleeve, and, the the locking portion comprises a protruding portion having a first face sloping outwardly from the elongated body portion of the stem along which the legs move during setting and a sloping portion extending in the opposite direction back to the stem body, forming a recess with the enlarged body portion.
 4. A set stem mechanism in accordance with claim 2 wherein: the stem bracket legs are resilient and taper inwardly from the periphery of the base portion, said legs having curved end portions which engage the set stem.
 5. A set stem mechanism in accordance with claim 2 wherein the watch includes a crown gear coupled to the minute wheel, said mechanism further including: a crown mounted to the end of the elongated body portion, said crown being moved outwardly from the watch during setting bringing the stem pinion into mesh with the crown gear for effecting movement of the minute wheel, and the locking portion comprises a protruding portion which forces the stem legs apart from a first locked position until the legs move into a second locked position for setting. 